ASSISTANCE DEVICE FOR A FREE-TURBINE ENGINE OF AN AIRCRAFT HAVING AT LEAST TWO FREE-TURBINE ENGINES

• US 20180187604A1
• Filed: 03/26/2015
• Published: 07/05/2018
• Est. Priority Date: 03/27/2014
• Status: Active Grant

• Current Assignee: Safran Helicopter Engines
• Original Assignee: Safran Helicopter Engines
• Granted Patent: US 10,151,246 B2
• Time in Patent Office: Days
• CPC Class Codes: B64C 27/12 Rotor drives
• CPC Class Codes: B64D 35/02 specially adapted for specific power plants
• CPC Class Codes: B64D 35/08 characterised by the transmission being driven by a plurality of power plants
• CPC Class Codes: F02C 3/10 with another turbine driving an output shaft but not driving the compressor
• CPC Class Codes: F02C 3/107 with two or more rotors connected by power transmission
• CPC Class Codes: F02C 7/262 Restarting after flame-out
• CPC Class Codes: F02C 7/275 Mechanical drives
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• CPC Class Codes: F02C 7/36 Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user F02C3/107 - F02C3/13 and F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H
• CPC Class Codes: F02C 9/42 specially adapted for the control of two or more plants simultaneously
• CPC Class Codes: F05D 2220/329 in helicopters
• CPC Class Codes: F05D 2220/76 an electrical generator
• CPC Class Codes: H02K 7/1823 structurally associated with turbines or similar engines
• CPC Class Codes: H02K 7/20 Structural association with auxiliary dynamo-electric machines, e.g. with electric starter motors or exciters
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

An assistance device for a free-turbine engine of an aircraft having at least two free-turbine engines, the device including an electrical starter machine for providing prolonged assistance to the gas generator of a first engine using energy produced by an electric generator machine driven by the second engine, the device further including at least one electricity storage member electrically connected to the electrical starter machine for providing a burst of assistance to the gas generator, wherein the electrical starter machine is powered by a first power converter enabling it to exchange energy with the storage member for providing the burst of assistance, and that transmits thereto the energy supplied by a second power converter for the prolonged assistance.

Claims

1. An assistance device for a free-turbine engine of an aircraft having at least two free-turbine engines, the device comprising an electrical starter machine and an electric generator machine, the electrical starter machine providing prolonged assistance to the gas generator of a first engine using energy produced by the electric generator machine driven by the second engine, the assistance device further comprising at least one electricity storage member electrically connected to said electrical starter machine for providing a burst of assistance to said gas generator, a first power converter and a second power converter, the electrical starter machine being powered by the first power converter to exchange energy with the storage member for providing the burst of assistance, and that transmits thereto the energy supplied by the second power converter for the prolonged assistance, the assistance device being characterized in that it further comprises a computer for cutting off the flow of fuel to the gas generator during a determined period during the prolonged assistance and for maintaining said gas generator at a reduced speed for facilitating re-ignition of said gas generator.

2. The assistance device according to claim 1, wherein a disconnector member enables the two converters to be electrically isolated from each other, the storage member remaining connected to the first converter.

3. The assistance device according to claim 1, wherein the first electrical machine is also a generator.

4. The assistance device according to claim 1, wherein the second electrical machine is driven by the gas generator of the second engine.

5. The assistance device according to claim 1, wherein a switch member enables the second converter to be connected to the electrical storage member.

6. The assistance device according to claim 1, wherein the second converter is powered by a generator electrical machine driven by the gas generator of a second engine of the aircraft.

7. The assistance device according to claim 1, wherein the electricity storage member can be used, where appropriate, for assisting in controlled acceleration or deceleration of said gas generator under twin-engined flight conditions.

8. The assistance device according to claim 1, including one storage element per engine in order to participate in burst accelerations of the gas generators of either of the engines.

9. The assistance device according to claim 1, wherein the computer maintains the flow of fuel to the gas generator for a determined period during prolonged assistance and it reduces the speed of the gas generator so as to minimize fuel consumption.

10. The assistance device according to claim 1, wherein the electricity storage member comprises a supercapacitor, a hybrid competitor, a lithium-ion battery, or a flywheel having an integrated DC/AC converter.

11. The assistance device according to claim 1, wherein the electricity storage member is recharged by taking energy from the gas generator of the first or second engine during periods in which said gas generator is supplied with fuel.

12. The aircraft having at least two free-turbine engines, and including an assistance device according to claim 1.